"humBill" wrote in message
ups.com...
On Mar 30, 8:11 pm, ~ jan wrote:
On Fri, 30 Mar 2007 16:19:51 CST, "drsolo" wrote:
polyester batting will most definitely take out algae.

I agree, so will open cell foam. The reason a filter appears not to
remove
it, is that on a nice sunny day, the algae can reproduce faster than most
filters can remove it.

My example is when I used garden soil in two pots that my son had added
steer manure to just the week before. Such bright green water you had to
wear shades, but come nightfall the filter would clear it up. Sun up,
bright green again. The pots came out, some big water changes, and no
more
algae creation. ~ jan
------------
Zone 7a, SE Washington State

I will not dispute that batting or even open cell foam removes algae.
But I am interested in the process. As best I can tell most pond
algae is between 15 and 45 microns. So it seems unlikely that per see
either one of these materials is filtering out live algae. Perhaps it
is stopping dead algae which has a tendency to clump. Perhaps
removing the dead algae leaves less nutrients in the water for the
live algae. It also seems beneficial bacterial may have some role in
killing off algae.

So I am not saying these materials don't help/work. I am just curious
why they do, since it seems a diatom filter is actually the only media
small enough to prevent the diameter of the algae from going through
the media.

A biological filter works because the bacteria that colonizes in it "eats"
and thrives on the same stuff that "algae bloom" does as the water passes
through it, starving the algae bloom. It doesn't strain the pond water the
way a mechanical filter does. When you add a bacteria supplement, you are
temporarily spiking the level of bacteria in your pond and filter. If your
filter material is dense enough to prevent algae from going through it, it
won't work biologically, only mechanically, and then only till it plugs up.
Your pond water will still be loaded with nutrients to grow the free
floating, suspended algae, and still be cloudy or a swamp
Gale :~)